Species recovery Captive breeding programs of endangered animals have the potential to send disease out into vulnerable animal communities, a new study shows.

The Australian research reveals brush-tail wallabies raised in a captive breeding program carry antibiotic resistance genes in their gut bacteria.

Dr Michelle Power, of Macquarie University, says when these animals are released they can transmit these antibiotic resistance genes into wild populations.

She says the finding has implications for species recovery programs and the release of animals back into the wild.

"It highlights the importance of health screening before release and trying to understand what is happening at the microbial level," she says

The paper published today in PLOS One, shows that nearly half the faecal samples collected from wallabies raised in a captive breeding program in New South Wales contained genes that encode resistance to antibiotics.

However none of these genes were found in faecal samples collected from five wild populations across NSW ranging in size from five to 20 individual animals.

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Power says they have been unable to pinpoint how the antibiotic resistance was transmitted to the captive breeding wallabies.

However she says the wallabies involved in the study were reared in captivity for up to four years so it was likely water or feed was the main source.

The study highlights that the bacterial genes encoded resistance for streptomycin, spectinomycin and trimethopim - antibiotics commonly used in veterinary practice, and listed by the World Organisation for Animal Health as antimicrobials of veterinary importance.

"The loss of ability to successfully treat disease is detrimental to endangered species recovery programs," Power and colleagues write.

"It should be noted that the captive wallabies described here acquired their integrons in the absence of antibiotic therapy."

Power says the finding also highlights the ease with which pathogens are transferred at the interface between humans and wildlife.

"Our study has confirmed the potential for transmission of disease organisms at the human, domestic animal and wildlife interface," she writes.

"To reduce the threat of disease through conservation practice, routine pathogen screening must be considered as an essential component of a management plan. Without such screening, animal translocation may alter host-pathogen interactions, further threatening already endangered species."